mips: add ethernet support for qca953x referenced boards

Signed-off-by: Rosy Song <rosysong@rosinson.com>
diff --git a/arch/mips/dts/ap143.dts b/arch/mips/dts/ap143.dts
index 6aedd87..2e23225 100644
--- a/arch/mips/dts/ap143.dts
+++ b/arch/mips/dts/ap143.dts
@@ -40,3 +40,8 @@
 		reg = <0>;
 	};
 };
+
+&gmac1 {
+	status = "okay";
+	phy-mode = "rgmii";
+};